Hydraulic ram unit



Sept. 3, 1957 Y E Sow N R m MNM n uw uw MAM f m wwe T ein@ ICTM IWW fw..YM

B \\V im Tn@ w f 1) Nw E wm. um ,5N W .QNQN QNNW! em. a S., ma, M\\ STHHHIIUMMH mm II m Il! uw mw w m v lll?! NN S Q mw .Q @www I .vm mw NQ @mm,S mww ww United States Patent F HYDRAULIC RAM UNIT Eugene V. Cyran,Birmingham, and Walter R. Jackson,

Rochester, Mich., assignors to Modern Service Engineering Co., Berkley,Mich., a corporation of Michigan Application January 18, 1954, SerialNo. 404,558

3 Claims. (Cl. 121-38) The present invention relates to a hydraulic ramunit adapted to perform punching, piercing and forming operations on asheet metal structure.

The illustrated embodiment of the present invention comprises a toolcarrying cylindrical ram having a piston therein on which the cylinderis advanced and retracted. The use of a movable cylinder and xed pistonmay be found in some conventional ram units. However, in suchconventional structures the piston means is generally supported by itsprotruding end on a rigid member and the cylinder is supported formovement on slide or guide ways. There are several objections withregard to such conventional ram unit construction. The machining andalignment of the ways on which the cylinder is slidable is acomplicated, time-consuming and expensive procedure. Also, the bearingsurface avail-able in such structure is substantially limited andaccordingly is subject to relatively rapid wear. The wear of the guideways results in misalignment of the piston with the cylinder causingexcessive wear therebetween. Further, in the conventional structure anymisalignment or looseness due to wear of the guideways is aggravatedwhen it is necessary to tilt the ram unit to perform operations onangularly situated surfaces of the workpiece.

'lt is an object of the present invention to provide a constructionwherein the foregoing objections to a conventional ram unit structureare eliminated. In the illustrated embodiment of the invention the toolcarrying cylinder or ram is journalled for axial movement within asubstantially cylindrical housing. It will be recognized that itrequires less effort to precision bore a cylindrical bearing surfacethan to machine a guide or slide way. Further, journalling thecylindrical ram in a cylindrical housing provides a maximum of bearingand support surface regardless of the angle of inclination at which itis necessary to operate the ram unit.

The present embodiment also includes an improved key device forpreventing rotation of the tool carrying cylinder or ram relative to thecylindrical housing. The improved key device includes means foradjusting the key when necessary to compensate for wear thereon.

Other objects, features and advantages of this invention will beapparent from the following description and appended claims, referencebeing had to the accompanying drawings forming a part of thisspecification wherein like reference numerals designate correspondingparts in the several views.

Fig. 1 is a vertical sectional View of a hydraulic ram unit constructedin accordance with the present invention.

Fig. 2 is a view in part sectional taken substantially along the line 22 of Fig. l looking in the direction of the arrows.

Fig.V 3 is a sectional viewtaken substantially along the `line`33 ofFig. 2 looking in the direction of the arrows.

Fig. 4 is a diagrammatic view of a simplified hydraulic 2,804,849Patented Sept. 3, 1957 ICC circuit for operating the ram unit embodyingthe present invention. y

Beforer explaining in detail the present invention it is to beunderstood that the invention is not limited in its application to thedetails of construction and arrangement of parts illustrated in theaccompanying drawing, since the invention is capable of otherembodiments and of being practiced or carried out in various ways. Alsoit is to be understood that the phraseology or terminology employedherein is for the purpose of description and not of limitation.

In the drawings there is illustrated by way of example, one embodimentof the present invention as applied to a piercing or punching mechanism.The mechanism comprises a cylindrical housing or body, generallydesignated 10, which is adapted to be secured to a table surface 11.Slidable within the bore 12 of the cylindrical housing 10 is a cylinder13. The cylinder 13 is, as will more fully be explained, the main toolcarrying cylinder or ram 0f the present device.

The cylinder 13 is provided with a bore 14 within which operates apiston 15. The piston 15 is provided with a rod 16 secured to a collaror end cap 17 by a nut 1S and a lock nut 19. The end cap 17 is securedto the -cylindrical housing or body 10 by means of screws 20, the endcap, however, being spaced from the body by a barrel or spacer ring 21.The piston 15 is thus secured to the housing 10 and is rigidly heldagainst movement relative thereto.

The left end of the cylinder ram bore 14, as viewed in Fig. 1, isprovided with an end cap 22 secured to the end of the cylinder 12 byscrews 22a and through which the piston rod 16 projects. The end cap 22is provided with a suitable oil seal 22b to prevent leakage of hydrauliciluid.

Both the end cap 17 and the piston rod 16 are provided with iluidpassageways 23 and 24, respectively. To advance the'cylinder 13 to theright as viewed in Fig. l, fluid under pressure is admitted through theend cap 17 passageway 23. The pressure of this uid is exerted againstthe surface 25 of end cap 22 thus causing the cylinder 13 to moveYtoward the right as viewed in Fig. 1. Conversely, to retract thecylinder 13, that is, to move it to the'left, duid under pressure isadmitted through passageway 24 to the bore 14 of the cylinder 13 and thepressure is exerted on the surface 26 of end cap V22. Suitable oil sealsare provided to prevent Huid leakage. One such seal 27 is providedbetween the piston 15 and the walls of the bore 14. Also, oil rings 28are provided between adjacent surfaces of the end cap 17 and the barrelor spacerring 21, and the barrel or spacer ring 21 and the walls of thebore 12 of the body 10.' An oil seal 29 is also provided between thecylinder 13 and the left end of the bore 12 of the body 10. There isalso an oil seal Stl'carried in the end cap 17 and surrounding thereduced end 16 of the piston rod 16. Y A

lt is to be understood that a simple conventional fluid system such asdiagrammatically illustrated in Fig. 4 for example, is employed todirect hydraulic'uid to and from the passageways 23 and 24 in propersequence. Fluid is directed from a pressure source, yrepresented by duidline 31 through a three position four way valve 32 into passagewayp23thereby causing the ram 13 to ad- Vance toward the right as viewed inFigs. l ,and 4. Any liuid in the chamber formed by bore 14 will beexhausted through passageway 24 through the valve 32 into discharge line33. Upon completion of theadvance moyement of ram 13, that is,completion of the punching or piercing operation, the valve 32 Will bemanipulated, manually or automatically as the case may be, to permit uidunder pressure to llow through passageway 24 into the chamber formed bythe bore 14 so as to act against surface'26 of end cap 22 to cause thecylinder or ram 14 to retract or move to the left as viewed in Fig. 1.Fluid in the chamber of theV barrel or spacer ring 21 will be eX-hausted through passageway23.

The rightend 34 of Vthe cylinder or ram 14 has" secured theretobymeansof -sc`rews"35`a mounting plate 36. `The mountingiplate Y36'hassecured. thereto byscrews `37 4an adaptor plate '33. The adaptor plate38 provides the means for supporting, Vin the present instance,` thepunch member 39. inthe `device `herein illustrated, by way of example,-the punch member 39'coacts witha die element 40 `mounted in asupportmember 41, thepunch'member 39and die element 40 forming a punch'coupletforpiercing holes 4in a sheet of material. It is to be understood thatVthe element -and^member-may-b`e a formingv die couplet for'forminga'piece Aof -rnetal to a desired shape. -The adaptor `plate 38 isillustrated as supportingva pressure plate or stripper element 42. The`adaptor plate 38 is provided with openings 43 therein through whichstuds 44 extend, Vthe'r'studs being threadedinto the stripper element.-The heads 45 of the studs are retractable in clearance holes 46 inthe-adaptor plate 318. Compression helical springs 47 are provided tonormally urge the stripper-elementaway from thefadaptor plate 38. Theoperativeend 48 of the punch member V39 projects through a port 49 in-thestripper element. t

The foregoing-construction and mounting of the stripper elementisconventional and the operation Vthereof may be `briefly stated. As theram 14 is moved to the right as viewed in Fig.. 1, the stripper element42 and the punch end'39 substantially simultaneously contact the surfaceof the workpiece. The punch end-will then penetrate the workpiece as thestripper element springs 47 are compressed. Upon retraction of the punchthe stripper element will. retain Vthe workpieceagainst the die elementsupport 41 until the punch end 139 has been withdrawn from theI punchedhole in the workpiece and again is flush with the surface of thestripper element, whereupon bothwpunch and stripper element will` beretracted in unison to the position shown in Fig. 1.

Asillustrated, the punch 39 is located axially of the ram 14 and theport 4.9 is correspondingly centrally located in the stripper plate.However, it will be readily understood that variations in the shape andlocation of the punch are possible. That is, the punch may be a compoundpunch or may have .to be located eccentrically of the ram axis toaccomplish thedesired result. Under such conditions, no angular rotationof the ram must occur otherwise the .punch will lose its criticalalignment with the yopposing dieelernent.Y In Figs. 2 and 3 there isillustrated an improved adjustable key means for preventing rotation ofthe cylinder or ram 13 relative to the housing or body 10.

It willbe noted that the tool carrying cylinder or ram 13 is providedwith arlongitudinally extending key slot .S0 having tapered side walls.Mounted 'on the front face 10a of the cylindrical'housing 10 is a key5,1 having a tapered nose portion S2 adapted to cooperate'with thetapered side walls of the key slot S0. The key 51' is mounted in a guideslot 53 in `the'housing face 10a and is .adapted to be moved radially ofthe Vcylinder or ram 13. A screw 54 is provided tolock the key inadjusted position. To further controlthe vadjustment of the key 51,there is provideda key adjuster S5. The key-51 at its lower edge isprovided with an inclined face 56 coacting with a cooperating orcomplementary, inclined face 57 on the key adjuster. The key' adjusterS5 is adjustable inwardly and `outwardly by means of an adjusting screw58, as best viewed in Fig.V 3. lInward movement or. movement to theright as viewed in Fig..3 will result in the key 51 being raisedradially of the cylinder or Aram 13. A set screw 59 is provided to lockthe key adjuster in adjusted position. It is believed apparent that thekey S1 may be adjusted to give the desired slipt of the key 51 in thekeyway 50 and to maintain the cylinder or ram 13 against any tendency to-rotate during its advancing and retracting movements.

Grease or loil cups 59 are provided leading to lubrication passageways60 in the housing 10, which passageways surround the cylinder or ram 13.

It will be noted in Fig. 1 thatthe bore 14 is provided with a ventopening into the keyway 50. This vent serves a dual function; Onmovement Aof the cylinder or ram 13 to the right as viewed in Fig. lJrelative to the piston 1S the vent 70 provides an opening by which airmay be sucked into the bore 14 to prevent a retarding vacuum from beingcreated. On return movement of the ram or cylinder 13, the air inchamber 14 will be exhausted through the vent 70 and will blow down thekeyway Si) keeping the keyway free of foreign matter.

it will be noted that the area of the surface 25 of the end cap 22against which the iluid pressure acts to ad- Vance the ram 13 lis largerthan the area of the 'surface 26 of the end cap-22 against which thepressure acts to retract the ram. Thus, the force exerted by the ram inits operating stroke is greaterfthan the force exerted `during theretracting stroke the desirability of which is believedreadilyfapparent. Further, since the volume of fluid required to advancethe ram is greater than required to retract the ram, thefram will beretracted faster than it advances inV order toaccommodate the flow offluid from the pressure source, i. e., the pump. This feature also isadvantageous in that it cuts down the non-operating time of the ramunit.

Although only one hydraulicram unit is illustrated, it will beunderstood that any number Iof units may be grouped on the work tabledepending upon the number of piercing,punching or vforming operationstobe performedyThe marmerv in which they ram or `tool carryingcylinder13 is journalled in the cylindricalhousing lor body 10 ensuresthat the ram will be fully supported and guided in its axial movementsregardless of the angle of inclination at which the ram unit maybepositioned. Also, Vinasmuch as the ram 13 is surrounded by bearingsurface it is better able to resist any tendency to become misalignedthrough force components acting in other than an axial directiom Thus,it is notmaterial that'the axis of the punch be concentric with the axisof the ram 13 and off center holes may be readily pierced or punchedwithout materially affecting the valignment V.of the ram with its guidesurfaces.

Further, it is believed readily apparent that the cost of manufacturingthe present ram unit will be materially less than the cost ofmanufacturing a unit wherein the cylinder or ram 13 -isA guided on slideways. It is much easier to precision bore a guide surface like the bore12 of the body 10 and to t a cylinder or ram unit 13 therein than tomachine and Aalign guide or slide ways and to t a slide carriagethereon. Also, in the present embodiment, the axis ofthe piston 15, theram 13 and the bore 12 of the body 10 are coincident which facilitatesthe alignment of these parts and results in a ram unit which is subjectto a minimum of wear dueV to misalignment.

We claim:

1. A device for performing punching operations or the like on-a piece ofwork, comprising a body member having a longitudinally extendingvinternally cylindrical ram receiving portion, a tool carryingcylindrical ram journalled for axial movement within said' ram receivingportion, a piston means within said ram and connected to said bodymember whereby 'said piston .means is im-V movable relative to said bodymember, fluid means for axially moving said ramin either directionrelative to said body member and piston v-Ineans,'said ram having alongitudinally extending keyslot in the outer surface thereof, key meanscarried bysaid -body member, and wedge means for adjusting saidkey'meansd radially of saidrarn to compensate for wear and to maintainthe latter in bearing engagement with the key-slot walls, said kkeymeans and key-slot preventing turning movement of said ram relative tosaid body during axial movement of said ram.

2. A device for performing punching operations or the like on a piece ofwork, comprising a body member having a longitudinally extendingcylindrical ram receiving portion, a tool carrying cylindrical ramjournalled for axial movement Within said ram receiving portion, apiston means within said ram and connected to said body member wherebysaid piston means is immovable relative to said body member, iluid meansfor axially moving said ram in either direction relative to said bodymember and piston means, said ram having a longitudinally extendingkeyslot in the outer surface thereof, said key-slot having tapered sidewalls, key means carried by said body member having a tapered endportion complementary to the tapered side walls of said key-slot, andwedge means carried by said body member adjustable to move said keymeans radially of said ram to maintain the same in bearing engagementwith the key-slot walls, said key means and key-slot preventing turningmovement of said ram relative to said body during axial movement of saidram.

3. A device for performing punching operations or the like on a piece ofWork, comprising a body member having a longitudinally extendinginternally cylindrical ram receiving portion, a tool carryingcylindrical ram j ournalled for axial movement within said ram receivingportion,

a piston means Within said ram and connected to said body member wherebysaid piston means is immovable relative to said body member, fluid meansfor axiall] moving said ram in either direction relative to said bodymember and piston means, said ram having a longitudinally extendingkey-slot in the outer surface thereof, said key-slot having tapered sideWalls, key means carried by said body member having a tapered endportion complementary to the tapered side walls of said key-slot, andWedge means carried by said body member adjustable in a directionaxially of said ram to move said key means radially of said ram tomaintain the same in bearing engagement with the key-slot Walls, saidkey means and key-slot preventing turning movement of said ram relativeto said body during axial movement of said ram.

References Cited in the file of this patent UNITED STATES PATENTS1,509,000 Simpson Sept. 16, 1924 2,112,153 Gorham Mar. 22, 19382,204,649 Barnhart June 18, 1940 2,353,488 Mueller July l1, 19442,504,406 Gandup Apr. 18, 1950 2,586,695 Mueller Feb. 19, 1952 2,660,319Dorland Nov. 24, 1953

